DNAprint Genomics (DNAG)

[mingwan0]

Here's another interesting paper:

Bonilla C, Bertoni B, Gonzalez S, Cardoso H, Brum-Zorrilla N, Sans M. Substantial native American female contribution to the population of Tacuarembo, Uruguay, reveals past episodes of sex-biased gene flow. Am J Human Biol. 2004 May-Jun;16(3):289-97.

National Human Genome Center, Howard University, Washington, DC 20060.

For many years it has been assumed that the population of Uruguay is almost exclusively European-derived and that the biological contribution of the native population as well as of individuals of African descent is negligible. Several recent studies based on a variety of genetic markers, mostly morphological and serological markers, have produced quite a different picture of the constitution of the Uruguayan population. The Native American contribution varies from 1-20%, while the African contribution ranges from 7-15%, in different regions of the country. In the present study we examine the way the admixture process took place in Uruguay by analyzing the ancestry of maternal lineages in a sample from the northern city of Tacuarembo. To accomplish this goal we typed mitochondrial DNA (mtDNA) markers of Native American, African, and European origin and estimated the proportions of each parental group in the admixed population. We found that 62% of all mtDNA haplogroups were of Native American descent, a surprising figure considering the "European roots" of the country. Consequently, this result assimilates Uruguay to the rest of Latin American populations where sex-biased gene flow between European men and Native American women has been the rule. We further analyzed the distribution of the four major founding mitochondrial lineages in Tacuarembo and compared it to other South American populations. We discuss our findings in the light of historical records and assess the need for additional genetic studies. Am. J. Hum. Biol. 16:289-297, 2004. Copyright 2004 Wiley-Liss, Inc.

And who is Carolina Bonilla?

http://anthro.psu.edu/biolab/crew/

Carolina Bonilla, Ph.D. recent graduate in biological anth, Part-Native Guide, [e-mail]

Here are her publications:

Bonilla C, Parra EJ, Pfaff CL, Dios S, Marshall JA, Hamman RF, Ferrell RE, Hoggart CL, McKeigue PM, Shriver MD. Admixture in the Hispanics of the San Luis Valley, Colorado, and its implications for complex trait gene mapping. Ann Hum Genet. 2004 Mar;68(Pt 2):139-53.

Hoggart CJ, Parra EJ, Shriver MD, Bonilla C, Kittles RA, Clayton DG, McKeigue PM. Control of confounding of genetic associations in stratified populations. Am J Hum Genet. 2003 Jun;72(6):1492-1504.

Shriver MD, Parra EJ, Dios S, Bonilla C, Norton H, Jovel C, Pfaff C, Jones C, Massac A, Cameron N, Baron A, Jackson T, Argyropoulos G, Jin L, Hoggart CJ, McKeigue PM, Kittles RA. Skin pigmentation, biogeographical ancestry and admixture mapping. Hum Genet. 2003 Apr;112(4):387-99. Epub 2003 Feb 11.

Akey JM, Sosnoski D, Parra E, Dios S, Hiester K, Su B, Bonilla C, Jin L, Shriver MD. Melting curve analysis of SNPs (McSNP): a gel-free and inexpensive approach for SNP genotyping. Biotechniques. 2001 Feb;30(2):358-62, 364, 366-7.

Parra EJ, Kittles RA, Argyropoulos G, Pfaff CL, Hiester K, Bonilla C, Sylvester N, Parrish-Gause D, Garvey WT, Jin L, McKeigue PM, Kamboh MI, Ferrell RE, Pollitzer WS, Shriver MD. Ancestral proportions and admixture dynamics in geographically defined African Americans living in South Carolina. Am J Phys Anthropol. 2001 Jan;114(1):18-29.

Pfaff CL, Parra EJ, Bonilla C, Hiester K, McKeigue PM, Kamboh MI, Hutchinson RG, Ferrell RE, Boerwinkle E, Shriver MD. Population structure in admixed populations: effect of admixture dynamics on the pattern of linkage disequilibrium. Am J Hum Genet. 2001 Jan;68(1):198-207. Epub 2000 Dec 07.

Maybe it's just me, but there seems to be a pattern here...

Incidentally, there was another recent paper on sex-biased admixture:

Wen B, Xie X, Gao S, Li H, Shi H, Song X, Qian T, Xiao C, Jin J, Su B, Lu D, Chakraborty R, Jin L. Analyses of genetic structure of tibeto-burman populations reveals sex-biased admixture in southern tibeto-burmans. Am J Hum Genet. 2004 May;74(5):856-65.

State Key Laboratory of Genetic Engineering and Center for Anthropological Studies, Fudan University, Shanghai 200433, China. [e-mail]

An unequal contribution of male and female lineages from parental populations to admixed ones is not uncommon in the American continents, as a consequence of directional gene flow from European men into African and Hispanic Americans in the past several centuries. However, little is known about sex-biased admixture in East Asia, where substantial migrations are recorded. Tibeto-Burman (TB) populations were historically derived from ancient tribes of northwestern China and subsequently moved to the south, where they admixed with the southern natives during the past 2,600 years. They are currently extensively distributed in China and Southeast Asia. In this study, we analyze the variations of 965 Y chromosomes and 754 mtDNAs in >20 TB populations from China. By examining the haplotype group distributions of Y-chromosome and mtDNA markers and their principal components, we show that the genetic structure of the extant southern Tibeto-Burman (STB) populations were primarily formed by two parental groups: northern immigrants and native southerners. Furthermore, the admixture has a bias between male and female lineages, with a stronger influence of northern immigrants on the male lineages (~62%) and with the southern natives contributing more extensively to the female lineages (~56%) in the extant STBs. This is the first genetic evidence revealing sex-biased admixture in STB populations, which has genetic, historical, and anthropological implications.